refactor: rename ws adapter to server across codebase

'ws' conflated storage mode with transport protocol (WebSocket). Renamed for
clarity: the adapter talks the self-hosted server (src/storage/server.js), which
happens to use WebSocket for realtime — but the name should describe what it
connects to, not how.

Renames:
- src/storage/ws.js -> server.js
- createWsStorage() -> createServerStorage()
- storage mode 'ws' -> 'server'
- REACT_APP_BACKEND_WS -> REACT_APP_BACKEND_REALTIME_URL
- factory param wsUrl -> realtimeUrl
- server/tests/ws-*.test.js -> server-*.test.js

Kept literal: 'ws' npm package, ws:// protocol URLs, /ws WebSocket endpoint.
Transport is accurate there; only storage-naming changed.

Updated all docs (DEVELOPMENT, TESTING, REWORK_PLAN, GLOSSARY, TODO), scripts
(dev-start.sh, replay-combat.js), factory + ESM tests. 204 tests green.

docs/TESTING.md

@@ -194,11 +194,11 @@ curl http://127.0.0.1:4001/health   # → {"ok":true}
 
 Never db in `/tmp` (wipe risk). Use `./data/` (gitignored) or docker volume.
 
-### Frontend (ws mode)
+### Frontend (server mode)
 ```bash
-REACT_APP_STORAGE=ws \
+REACT_APP_STORAGE=server \
 REACT_APP_BACKEND_URL=http://127.0.0.1:4001 \
-REACT_APP_BACKEND_WS=ws://127.0.0.1:4001/ws \
+REACT_APP_BACKEND_REALTIME_URL=ws://127.0.0.1:4001/ws \
 BROWSER=none PORT=3999 \
 npm start
 ```
@@ -210,10 +210,9 @@ Firebase mode (default): set `REACT_APP_FIREBASE_*` in `.env.local` (copy `env.e
 
 `STORAGE_MODE = getStorageMode()` reads `REACT_APP_STORAGE`:
 - `firebase` (default) → real SDK
-- `ws` → backend (docker/prod)
-- `memory` → in-process (test seed)
+- `server` → backend (docker/prod)
 
-All adapters ESM. Adapter contract: `src/storage/contract.js` — same spec vs memory/ws/firebase.
+All adapters ESM. Adapter contract: `src/storage/contract.js` — same spec vs server/firebase.
 
 ## Known RED / backlog